DESCRIPTION (Adapted from applicant's description): Funds are being sought to continue the Cold Spring Harbor Laboratory course on "Cell and Developmental Biology of Xenopus which has been taught for seven years as part of an integrated set of courses in a number of areas of modern biology. The course is suited both for those who have a knowledge of molecular biology and developmental biology, but have had no experience with Xenopus, as well as those with some Xenopus experience who wish to learn newly developed, advanced techniques. The specific areas that will be covered are: 1) Care and handling of Xenopus adults, removal of oocytes, induction of ovulation, egg collection, testis isolation, and in vitro and natural fertilization; 2) Stages of embryonic development and anatomy; 3) Whole mount in situ hybridization and immunohistochemistry, including double probe staining; 4) Microinjection of eggs and oocytes with lineage tracers, mRNA and DNA constructions; 5) Use of oocytes to make conditioned medium containing growth factors; 6) Micromanipulation of embryos, including induction and transplantation assays; 7) Oligonucleotide antisense techniques for "Knock- out" of maternal molecules; 8) Preparation and use of cell cycle extracts for construction of transgenic embryos; and 9) Use of Xenopus tropicalis as a genetic model.